Storage devices enable storage and retrieval of data. Examples of storage devices include volatile memory devices and non-volatile memory devices. A non-volatile memory retains data after a power-down event. In some cases, volatile memories enable low latency (e.g., fast read and write speeds).
Some storage devices include a non-volatile memory and a volatile memory to enable fast read and write speeds in connection with data retention after a power-down event. For example, a storage device may include a flash memory and a dynamic random access memory (DRAM). Prior to a power-down event, data stored at the DRAM may be transferred to the flash memory. In response to a power-up event, the data may be read from the flash memory and transferred to the DRAM. Transferring data from the DRAM to the flash memory (and vice versa) consumes time and power. In addition, use of multiple memory types in a storage device may cause high fabrication cost.
Some storage devices include a “universal” memory that functions as a non-volatile memory and as a volatile memory. A universal memory may be associated with fast read and write speeds and a relatively high bit error rate (BER). Data may be encoded using a relatively “strong” ECC scheme (e.g., using a large number of redundancy bits) to compensate for the relatively high BER (but use of the “strong” ECC scheme increases latency of read and write operations). As a result, universal memories are not widely used.